rake aborted: expected SCALAR, SEQUENCE-START, MAPPING-START, or ALIAS

[endersonmaia]

I'm getting this error using activerecord-sqlserver-adapter.

app> $ RAILS_ENV=production rake db:data:dump --trace
** Invoke db:data:dump (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute db:data:dump
rake aborted!
expected SCALAR, SEQUENCE-START, MAPPING-START, or ALIAS
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:24:in `scalar'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:24:in `visit_Psych_Nodes_Scalar'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:29:in `block in visit_Psych_Nodes_Sequence'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:29:in `each'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:29:in `visit_Psych_Nodes_Sequence'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:29:in `block in visit_Psych_Nodes_Sequence'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:29:in `each'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:29:in `visit_Psych_Nodes_Sequence'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:29:in `block in visit_Psych_Nodes_Sequence'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:29:in `each'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:29:in `visit_Psych_Nodes_Sequence'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:19:in `block in visit_Psych_Nodes_Document'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:19:in `each'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:19:in `visit_Psych_Nodes_Document'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:13:in `block in visit_Psych_Nodes_Stream'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:13:in `each'
/usr/lib/ruby/1.9.1/psych/visitors/emitter.rb:13:in `visit_Psych_Nodes_Stream'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
/usr/lib/ruby/1.9.1/psych/nodes/node.rb:46:in `to_yaml'
/usr/lib/ruby/1.9.1/psych.rb:190:in `dump'
/usr/lib/ruby/1.9.1/psych/core_ext.rb:14:in `psych_to_yaml'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/yaml_db.rb:27:in `chunk_records'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/yaml_db.rb:49:in `block in dump_table_records'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/serialization_helper.rb:186:in `block in each_table_page'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/serialization_helper.rb:182:in `each'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/serialization_helper.rb:182:in `each_table_page'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/yaml_db.rb:47:in `dump_table_records'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/serialization_helper.rb:167:in `dump_table'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/serialization_helper.rb:150:in `block in dump'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/serialization_helper.rb:148:in `each'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/serialization_helper.rb:148:in `dump'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/serialization_helper.rb:14:in `dump'
/var/lib/gems/1.9.1/gems/yaml_db-0.3.0/lib/tasks/yaml_db_tasks.rake:21:in `block (3 levels) in '
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/task.rb:240:in `call'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/task.rb:240:in `block in execute'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/task.rb:235:in `each'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/task.rb:235:in `execute'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
/usr/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/task.rb:165:in `invoke'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/application.rb:150:in `invoke_task'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/application.rb:106:in `each'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/application.rb:106:in `block in top_level'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/application.rb:115:in `run_with_threads'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/application.rb:100:in `top_level'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/application.rb:78:in `block in run'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/application.rb:176:in `standard_exception_handling'
/var/lib/gems/1.9.1/gems/rake-10.4.2/lib/rake/application.rb:75:in `run'
/var/lib/gems/1.9.1/gems/rake-10.4.2/bin/rake:33:in `'
/usr/local/bin/rake:19:in `load'
/usr/local/bin/rake:19:in `'
Tasks: TOP => db:data:dump

Some info about my environment :

# bundle show
Gems included by the bundle:
  * actionmailer (3.2.22)
  * actionpack (3.2.22)
  * activemodel (3.2.22)
  * activerecord (3.2.22)
  * activerecord-sqlserver-adapter (3.2.13)
  * activeresource (3.2.22)
  * activesupport (3.2.22)
  * arel (3.0.3)
  * builder (3.0.4)
  * bundler (1.3.5)
  * coderay (1.1.0)
  * erubis (2.7.0)
  * hike (1.2.3)
  * i18n (0.6.11)
  * journey (1.0.4)
  * jquery-rails (3.1.3)
  * json (1.8.3)
  * mail (2.5.4)
  * mime-types (1.25.1)
  * multi_json (1.11.2)
  * net-ldap (0.3.1)
  * polyglot (0.3.5)
  * rack (1.4.7)
  * rack-cache (1.2)
  * rack-openid (1.4.2)
  * rack-ssl (1.3.4)
  * rack-test (0.6.3)
  * rails (3.2.22)
  * railties (3.2.22)
  * rake (10.4.2)
  * rbpdf (1.18.6)
  * rdoc (3.12.2)
  * redcarpet (2.3.0)
  * request_store (1.0.5)
  * rmagick (2.13.4)
  * ruby-openid (2.3.0)
  * sprockets (2.2.3)
  * thor (0.19.1)
  * tilt (1.4.1)
  * tiny_tds (0.6.2)
  * treetop (1.4.15)
  * tzinfo (0.3.44)
  * yaml_db (0.3.0)

# ruby --version
ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-linux]